This invention relates to pick-proof locks where a key sets a series of lock-controlling elements and is then isolated from these elements. At the same time, the lock entrance keyslot is also isolated from the lock-controlling elements. This makes it impossible for any picking tool to reach the lock-opening mechanism thru the key slot.
The general philosophy of this lock follows the basic concepts embodied in the U.S. Pat. No. 4,599,877 issued to me on July 15, 1986. In that patent it was the key itself that set the lock opening elements into their prescribed positions. The key and the key passage were then isolated from the elements before the lock could be opened. The resulting designs were rather complicated and there was the additional difficulty that the key cylinder had to be rather thin so that a good part of the key had to be exposed to be able to set the elements. The locks described in that patent required a separate mechanism to accomplish the key-isolation. In most cases this required a separate cylinder or gate, geared to the key cylinder.
In the present invention, the key isolation is accomplished in a far simpler and more novel manner.